1. Field of the Invention
The present application relates to an optical transceiver, in particular, the application relates to an optical transceiver whose architecture follows standards defined by multi sources.
2. Background Arts
Optical transceivers, in particular, pluggable optical transceivers generally follow multi-source agreements (hereafter denoted as “MSA”) for electronic and mechanical specifications thereof. For instance, one of the MSAs regarding to, what is called, the small form factor pluggable (SFP) defines several control signals called as MOD_DEF0, MOD_DEF1 and MOD_DEF2. Another MSA called as the XFP (10 Gbit Small Form Factor Pluggable) also defines control signals, or control pins of Mod_Abs, Mod_DeSel, P_Down, and Tx_DIS.
In another aspect, the optical transceivers are necessary to be revised in a control program thereof. The optical transceivers generally provide a controller to execute a program stored in the controller to monitor or detect statuses within the optical transceiver. The program is necessary to be revised by downloading a new program from an external system. However, the SFP transceivers and/or the XFP transceivers have no extra terminals available for downloading the program. Several techniques to download a new program, namely, a revised program, have been proposed. For instance, the revised program is to be transferred in a form of optical signals by using an optical receiver installed in the optical transceiver.